This project will analyze longitudinal patterns of services utilization and cost of care by persons with HIV disease participating in the New Jersey Medicaid program a from a cohort of participants in a home and community based waiver program will be enhanced and extended, and data on non-waiver participants will be added. Utilization by waiver and non- waiver participants will be compared and data from both populations will be used to model utilization trajectories in a multivariate framework using repeated-measures and event history models. These models will focus on the determinants of utilization of inpatient, outpatient, home care, pharmaceutical, and other services both in terminal and non-terminal stages of illness. Fixed-effects and random-effects models will be utilized to analyze per-month costs at different points in the course of illness. Frequency and length of hospitalizations, frequency of outpatient visits, rates of antiviral treatment and prophylaxis, and total cost of care for waiver and non-waiver populations will be analyzed. Trajectories of functional status will be modeled using longitudinal interview data with an average of 10 monthly followups per respondent, and the relationships among functional status, informal caregiving, and the use of formal home care services will be modeled. The enhanced data sets will be used to provide a better understanding of the determinants of utilization and costs in HIV illness, to better understand the effects of providing case management and home-based services on utilization and cost, and to demonstrate an analytic framework generalizable to studies of other chronic conditions.